1. Field of the Invention
The present invention generally relates to large caliber projectile ammunition and, more particularly, to a primer-propellant electrical ignition interconnect arrangement for both single and multiple piece ammunition.
2. Description of the Prior Art
The evolution of large caliber ordnance has led to the development of ammunition with increased lethality and correspondingly to weapon systems with increased armor protection in defense. As larger calibers of guns and projectiles have been developed, propulsion-ignition systems have grown in size and in energy content to give progressively higher projectile velocities and in-bore pressures. The pressure effects of violently exploding propellant create pressure shock waves which, if not properly controlled, can inflict damage to the projectile prior to its expulsion from the gun muzzle.
Presently, some large caliber ordnance has outstripped the capability of soldiers to lift an entire round into the gun breech. This has led to the design of multiple piece ammunition in which the first loaded piece contains the projectile and successive piece(s) contain additional propellant. As with most ammunition, the last piece contains the propellant igniter, or primer.
With the current single and multiple piece ammunition, only one ignition point exists to propagate the explosive combustion of the propellant throughout the cartridge or container. In large caliber gun systems, the propulsion system propagation time may be too slow to provide maximum efficiency of energy provided by the burning propellant. Many pyrotechnic schemes have been devised to accelerate the combustion of propellant with moderate success.
In multiple piece ammunition, the primary inhibitor to rapid combustion of cartridge propellants is the interface between separate cartridge pieces. Modern multiple piece ammunition trades off the rapidity of pyrotechnic propagation devices for rugged but combustible cartridge cases. Since most large caliber ignition devices are electrically activated by hot wire, or bridge wire devices, the approach of placing one of these electro-explosive devices per cartridge has been tried but with little success.
The lack of success experienced with using multiple electro-explosive devices derives from the bridge wire's unpredictable initiation time. Typically, the wire's ability to initiate explosive materials varies by as much as a few milliseconds. With propellant combustion times of ten milliseconds or less for most ammunition, the cartridge-to-cartridge ignition times create enormous pressure shock waves which tend to break projectile stabilization fins and like projectile and gun system parts.
Consequently, a need exists for an effective arrangement to more precisely control electro-explosive device ignition times so as to overcome the problems experienced heretofore.